<?php

/**
 * @file
 * Implement an image field, based on the file module's file field.
 */

/**
 * Implements hook_field_info().
 */
function image_field_info() {
	return array(
			'image' => array(
					'label' => t('Image'),
					'description' => t('This field stores the ID of an image file as an integer value.'),
					'settings' => array(
							'uri_scheme' => variable_get('file_default_scheme', 'public'),
							'default_image' => 0,
					),
					'instance_settings' => array(
							'file_extensions' => 'png gif jpg jpeg',
							'file_directory' => '',
							'max_filesize' => '',
							'alt_field' => 0,
							'title_field' => 0,
							'max_resolution' => '',
							'min_resolution' => '',
					),
					'default_widget' => 'image_image',
					'default_formatter' => 'image',
			),
	);
}

/**
 * Implements hook_field_settings_form().
 */
function image_field_settings_form($field, $instance) {
	$defaults = field_info_field_settings($field['type']);
	$settings = array_merge($defaults, $field['settings']);

	$scheme_options = array();
	foreach (file_get_stream_wrappers(STREAM_WRAPPERS_WRITE_VISIBLE) as $scheme => $stream_wrapper) {
		$scheme_options[$scheme] = $stream_wrapper['name'];
	}
	$form['uri_scheme'] = array(
			'#type' => 'radios',
			'#title' => t('Upload destination'),
			'#options' => $scheme_options,
			'#default_value' => $settings['uri_scheme'],
			'#description' => t('Select where the final files should be stored. Private file storage has significantly more overhead than public files, but allows restricted access to files within this field.'),
	);

	// When the user sets the scheme on the UI, even for the first time, it's
	// updating a field because fields are created on the "Manage fields"
	// page. So image_field_update_field() can handle this change.
	$form['default_image'] = array(
			'#title' => t('Default image'),
			'#type' => 'managed_file',
			'#description' => t('If no image is uploaded, this image will be shown on display.'),
			'#default_value' => $field['settings']['default_image'],
			'#upload_location' => $settings['uri_scheme'] . '://default_images/',
	);

	return $form;
}

/**
 * Implements hook_field_instance_settings_form().
 */
function image_field_instance_settings_form($field, $instance) {
	$settings = $instance['settings'];

	// Use the file field instance settings form as a basis.
	$form = file_field_instance_settings_form($field, $instance);

	// Add maximum and minimum resolution settings.
	$max_resolution = explode('x', $settings['max_resolution']) + array('', '');
	$form['max_resolution'] = array(
			'#type' => 'item',
			'#title' => t('Maximum image resolution'),
			'#element_validate' => array('_image_field_resolution_validate'),
			'#weight' => 4.1,
			'#field_prefix' => '<div class="container-inline">',
			'#field_suffix' => '</div>',
			'#description' => t('The maximum allowed image size expressed as WIDTHxHEIGHT (e.g. 640x480). Leave blank for no restriction. If a larger image is uploaded, it will be resized to reflect the given width and height. Resizing images on upload will cause the loss of <a href="http://en.wikipedia.org/wiki/Exchangeable_image_file_format">EXIF data</a> in the image.'),
	);
	$form['max_resolution']['x'] = array(
			'#type' => 'textfield',
			'#title' => t('Maximum width'),
			'#title_display' => 'invisible',
			'#default_value' => $max_resolution[0],
			'#size' => 5,
			'#maxlength' => 5,
			'#field_suffix' => ' x ',
	);
	$form['max_resolution']['y'] = array(
			'#type' => 'textfield',
			'#title' => t('Maximum height'),
			'#title_display' => 'invisible',
			'#default_value' => $max_resolution[1],
			'#size' => 5,
			'#maxlength' => 5,
			'#field_suffix' => ' ' . t('pixels'),
	);

	$min_resolution = explode('x', $settings['min_resolution']) + array('', '');
	$form['min_resolution'] = array(
			'#type' => 'item',
			'#title' => t('Minimum image resolution'),
			'#element_validate' => array('_image_field_resolution_validate'),
			'#weight' => 4.2,
			'#field_prefix' => '<div class="container-inline">',
			'#field_suffix' => '</div>',
			'#description' => t('The minimum allowed image size expressed as WIDTHxHEIGHT (e.g. 640x480). Leave blank for no restriction. If a smaller image is uploaded, it will be rejected.'),
	);
	$form['min_resolution']['x'] = array(
			'#type' => 'textfield',
			'#title' => t('Minimum width'),
			'#title_display' => 'invisible',
			'#default_value' => $min_resolution[0],
			'#size' => 5,
			'#maxlength' => 5,
			'#field_suffix' => ' x ',
	);
	$form['min_resolution']['y'] = array(
			'#type' => 'textfield',
			'#title' => t('Minimum height'),
			'#title_display' => 'invisible',
			'#default_value' => $min_resolution[1],
			'#size' => 5,
			'#maxlength' => 5,
			'#field_suffix' => ' ' . t('pixels'),
	);

	// Remove the description option.
	unset($form['description_field']);

	// Add title and alt configuration options.
	$form['alt_field'] = array(
			'#type' => 'checkbox',
			'#title' => t('Enable <em>Alt</em> field'),
			'#default_value' => $settings['alt_field'],
			'#description' => t('The alt attribute may be used by search engines, screen readers, and when the image cannot be loaded.'),
			'#weight' => 10,
	);
	$form['title_field'] = array(
			'#type' => 'checkbox',
			'#title' => t('Enable <em>Title</em> field'),
			'#default_value' => $settings['title_field'],
			'#description' => t('The title attribute is used as a tooltip when the mouse hovers over the image.'),
			'#weight' => 11,
	);

	return $form;
}

/**
 * Element validate function for resolution fields.
 */
function _image_field_resolution_validate($element, &$form_state) {
	if (!empty($element['x']['#value']) || !empty($element['y']['#value'])) {
		foreach (array('x', 'y') as $dimension) {
			$value = $element[$dimension]['#value'];
			if (!is_numeric($value)) {
				form_error($element[$dimension], t('Height and width values must be numeric.'));
				return;
			}
			if (intval($value) == 0) {
				form_error($element[$dimension], t('Both a height and width value must be specified in the !name field.', array('!name' => $element['#title'])));
				return;
			}
		}
		form_set_value($element, intval($element['x']['#value']) . 'x' . intval($element['y']['#value']), $form_state);
	}
	else {
		form_set_value($element, '', $form_state);
	}
}

/**
 * Implements hook_field_load().
 */
function image_field_load($entity_type, $entities, $field, $instances, $langcode, &$items, $age) {
	file_field_load($entity_type, $entities, $field, $instances, $langcode, $items, $age);
}

/**
 * Implements hook_field_prepare_view().
 */
function image_field_prepare_view($entity_type, $entities, $field, $instances, $langcode, &$items) {
	// If there are no files specified at all, use the default.
	foreach ($entities as $id => $entity) {
		if (empty($items[$id]) && $field['settings']['default_image']) {
			if ($file = file_load($field['settings']['default_image'])) {
				$items[$id][0] = (array) $file + array(
						'is_default' => TRUE,
						'alt' => '',
						'title' => '',
				);
			}
		}
	}
}

/**
 * Implements hook_field_presave().
 */
function image_field_presave($entity_type, $entity, $field, $instance, $langcode, &$items) {
	file_field_presave($entity_type, $entity, $field, $instance, $langcode, $items);

	// Determine the dimensions if necessary.
	foreach ($items as &$item) {
		if (!isset($item['width']) || !isset($item['height'])) {
			$info = image_get_info(file_load($item['fid'])->uri);

			if (is_array($info)) {
				$item['width'] = $info['width'];
				$item['height'] = $info['height'];
			}
		}
	}
}

/**
 * Implements hook_field_insert().
 */
function image_field_insert($entity_type, $entity, $field, $instance, $langcode, &$items) {
	file_field_insert($entity_type, $entity, $field, $instance, $langcode, $items);
}

/**
 * Implements hook_field_update().
 */
function image_field_update($entity_type, $entity, $field, $instance, $langcode, &$items) {
	file_field_update($entity_type, $entity, $field, $instance, $langcode, $items);
}

/**
 * Implements hook_field_delete().
 */
function image_field_delete($entity_type, $entity, $field, $instance, $langcode, &$items) {
	file_field_delete($entity_type, $entity, $field, $instance, $langcode, $items);
}

/**
 * Implements hook_field_delete_revision().
 */
function image_field_delete_revision($entity_type, $entity, $field, $instance, $langcode, &$items) {
	file_field_delete_revision($entity_type, $entity, $field, $instance, $langcode, $items);
}

/**
 * Implements hook_field_is_empty().
 */
function image_field_is_empty($item, $field) {
	return file_field_is_empty($item, $field);
}

/**
 * Implements hook_field_widget_info().
 */
function image_field_widget_info() {
	return array(
			'image_image' => array(
					'label' => t('Image'),
					'field types' => array('image'),
					'settings' => array(
							'progress_indicator' => 'throbber',
							'preview_image_style' => 'thumbnail',
					),
					'behaviors' => array(
							'multiple values' => FIELD_BEHAVIOR_CUSTOM,
							'default value' => FIELD_BEHAVIOR_NONE,
					),
			),
	);
}

/**
 * Implements hook_field_widget_settings_form().
 */
function image_field_widget_settings_form($field, $instance) {
	$widget = $instance['widget'];
	$settings = $widget['settings'];

	// Use the file widget settings form.
	$form = file_field_widget_settings_form($field, $instance);

	$form['preview_image_style'] = array(
			'#title' => t('Preview image style'),
			'#type' => 'select',
			'#options' => image_style_options(FALSE),
			'#empty_option' => '<' . t('no preview') . '>',
			'#default_value' => $settings['preview_image_style'],
			'#description' => t('The preview image will be shown while editing the content.'),
			'#weight' => 15,
	);

	return $form;
}

/**
 * Implements hook_field_widget_form().
 */
function image_field_widget_form(&$form, &$form_state, $field, $instance, $langcode, $items, $delta, $element) {

	// Add display_field setting to field because file_field_widget_form() assumes it is set.
	$field['settings']['display_field'] = 0;

	$elements = file_field_widget_form($form, $form_state, $field, $instance, $langcode, $items, $delta, $element);
	$settings = $instance['settings'];

	foreach (element_children($elements) as $delta) {
		// Add upload resolution validation.
		if ($settings['max_resolution'] || $settings['min_resolution']) {
			$elements[$delta]['#upload_validators']['file_validate_image_resolution'] = array($settings['max_resolution'], $settings['min_resolution']);
		}

		// If not using custom extension validation, ensure this is an image.
		$supported_extensions = array('png', 'gif', 'jpg', 'jpeg');
		$extensions = isset($elements[$delta]['#upload_validators']['file_validate_extensions'][0]) ? $elements[$delta]['#upload_validators']['file_validate_extensions'][0] : implode(' ', $supported_extensions);
		$extensions = array_intersect(explode(' ', $extensions), $supported_extensions);
		$elements[$delta]['#upload_validators']['file_validate_extensions'][0] = implode(' ', $extensions);

		// Add all extra functionality provided by the image widget.
		$elements[$delta]['#process'][] = 'image_field_widget_process';
	}

	if ($field['cardinality'] == 1) {
		// If there's only one field, return it as delta 0.
		if (empty($elements[0]['#default_value']['fid'])) {
			$elements[0]['#description'] = theme('file_upload_help', array('description' => $instance['description'], 'upload_validators' => $elements[0]['#upload_validators']));
		}
	}
	else {
		$elements['#file_upload_description'] = theme('file_upload_help', array('upload_validators' => $elements[0]['#upload_validators']));
	}
	return $elements;
}

/**
 * An element #process callback for the image_image field type.
 *
 * Expands the image_image type to include the alt and title fields.
 */
function image_field_widget_process($element, &$form_state, $form) {
	$item = $element['#value'];
	$item['fid'] = $element['fid']['#value'];

	$instance = field_widget_instance($element, $form_state);

	$settings = $instance['settings'];
	$widget_settings = $instance['widget']['settings'];

	$element['#theme'] = 'image_widget';
	$element['#attached']['css'][] = drupal_get_path('module', 'image') . '/image.css';

	// Add the image preview.
	if ($element['#file'] && $widget_settings['preview_image_style']) {
		$variables = array(
				'style_name' => $widget_settings['preview_image_style'],
				'path' => $element['#file']->uri,
		);

		// Determine image dimensions.
		if (isset($element['#value']['width']) && isset($element['#value']['height'])) {
			$variables['width'] = $element['#value']['width'];
			$variables['height'] = $element['#value']['height'];
		}
		else {
			$info = image_get_info($element['#file']->uri);

			if (is_array($info)) {
				$variables['width'] = $info['width'];
				$variables['height'] = $info['height'];
			}
			else {
				$variables['width'] = $variables['height'] = NULL;
			}
		}

		$element['preview'] = array(
				'#type' => 'markup',
				'#markup' => theme('image_style', $variables),
		);

		// Store the dimensions in the form so the file doesn't have to be accessed
		// again. This is important for remote files.
		$element['width'] = array(
				'#type' => 'hidden',
				'#value' => $variables['width'],
		);
		$element['height'] = array(
				'#type' => 'hidden',
				'#value' => $variables['height'],
		);
	}

	// Add the additional alt and title fields.
	$element['alt'] = array(
			'#title' => t('Alternate text'),
			'#type' => 'textfield',
			'#default_value' => isset($item['alt']) ? $item['alt'] : '',
			'#description' => t('This text will be used by screen readers, search engines, or when the image cannot be loaded.'),
			// @see http://www.gawds.org/show.php?contentid=28
			'#maxlength' => 512,
			'#weight' => -2,
			'#access' => (bool) $item['fid'] && $settings['alt_field'],
	);
	$element['title'] = array(
			'#type' => 'textfield',
			'#title' => t('Title'),
			'#default_value' => isset($item['title']) ? $item['title'] : '',
			'#description' => t('The title is used as a tool tip when the user hovers the mouse over the image.'),
			'#maxlength' => 1024,
			'#weight' => -1,
			'#access' => (bool) $item['fid'] && $settings['title_field'],
	);

	return $element;
}

/**
 * Returns HTML for an image field widget.
 *
 * @param $variables
 *   An associative array containing:
 *   - element: A render element representing the image field widget.
 *
 * @ingroup themeable
 */
function theme_image_widget($variables) {
	$element = $variables['element'];
	$output = '';
	$output .= '<div class="image-widget form-managed-file clearfix">';

	if (isset($element['preview'])) {
		$output .= '<div class="image-preview">';
		$output .= drupal_render($element['preview']);
		$output .= '</div>';
	}

	$output .= '<div class="image-widget-data">';
	if ($element['fid']['#value'] != 0) {
		$element['filename']['#markup'] .= ' <span class="file-size">(' . format_size($element['#file']->filesize) . ')</span> ';
	}
	$output .= drupal_render_children($element);
	$output .= '</div>';
	$output .= '</div>';

	return $output;
}

/**
 * Implements hook_field_formatter_info().
 */
function image_field_formatter_info() {
	$formatters = array(
			'image' => array(
					'label' => t('Image'),
					'field types' => array('image'),
					'settings' => array('image_style' => '', 'image_link' => ''),
			),
	);

	return $formatters;
}

/**
 * Implements hook_field_formatter_settings_form().
 */
function image_field_formatter_settings_form($field, $instance, $view_mode, $form, &$form_state) {
	$display = $instance['display'][$view_mode];
	$settings = $display['settings'];

	$image_styles = image_style_options(FALSE);
	$element['image_style'] = array(
			'#title' => t('Image style'),
			'#type' => 'select',
			'#default_value' => $settings['image_style'],
			'#empty_option' => t('None (original image)'),
			'#options' => $image_styles,
	);

	$link_types = array(
			'content' => t('Content'),
			'file' => t('File'),
	);
	$element['image_link'] = array(
			'#title' => t('Link image to'),
			'#type' => 'select',
			'#default_value' => $settings['image_link'],
			'#empty_option' => t('Nothing'),
			'#options' => $link_types,
	);

	return $element;
}

/**
 * Implements hook_field_formatter_settings_summary().
 */
function image_field_formatter_settings_summary($field, $instance, $view_mode) {
	$display = $instance['display'][$view_mode];
	$settings = $display['settings'];

	$summary = array();

	$image_styles = image_style_options(FALSE);
	// Unset possible 'No defined styles' option.
	unset($image_styles['']);
	// Styles could be lost because of enabled/disabled modules that defines
	// their styles in code.
	if (isset($image_styles[$settings['image_style']])) {
		$summary[] = t('Image style: @style', array('@style' => $image_styles[$settings['image_style']]));
	}
	else {
		$summary[] = t('Original image');
	}

	$link_types = array(
			'content' => t('Linked to content'),
			'file' => t('Linked to file'),
	);
	// Display this setting only if image is linked.
	if (isset($link_types[$settings['image_link']])) {
		$summary[] = $link_types[$settings['image_link']];
	}

	return implode('<br />', $summary);
}

/**
 * Implements hook_field_formatter_view().
 */
function image_field_formatter_view($entity_type, $entity, $field, $instance, $langcode, $items, $display) {
	$element = array();

	// Check if the formatter involves a link.
	if ($display['settings']['image_link'] == 'content') {
		$uri = entity_uri($entity_type, $entity);
	}
	elseif ($display['settings']['image_link'] == 'file') {
		$link_file = TRUE;
	}

	foreach ($items as $delta => $item) {
		if (isset($link_file)) {
			$uri = array(
					'path' => file_create_url($item['uri']),
					'options' => array(),
			);
		}
		$element[$delta] = array(
				'#theme' => 'image_formatter',
				'#item' => $item,
				'#image_style' => $display['settings']['image_style'],
				'#path' => isset($uri) ? $uri : '',
		);
	}

	return $element;
}

/**
 * Returns HTML for an image field formatter.
 *
 * @param $variables
 *   An associative array containing:
 *   - item: An array of image data.
 *   - image_style: An optional image style.
 *   - path: An array containing the link 'path' and link 'options'.
 *
 * @ingroup themeable
 */
function theme_image_formatter($variables) {
	$item = $variables['item'];
	$image = array(
			'path' => $item['uri'],
			'alt' => $item['alt'],
	);

	if (isset($item['width']) && isset($item['height'])) {
		$image['width'] = $item['width'];
		$image['height'] = $item['height'];
	}

	// Do not output an empty 'title' attribute.
	if (drupal_strlen($item['title']) > 0) {
		$image['title'] = $item['title'];
	}

	if ($variables['image_style']) {
		$image['style_name'] = $variables['image_style'];
		$output = theme('image_style', $image);
	}
	else {
		$output = theme('image', $image);
	}

	if (!empty($variables['path']['path'])) {
		$path = $variables['path']['path'];
		$options = $variables['path']['options'];
		// When displaying an image inside a link, the html option must be TRUE.
		$options['html'] = TRUE;
		$output = l($output, $path, $options);
	}

	return $output;
}
